With the festive season upon us, many people will indulge in more alcohol than usual. The health risks of binge drinking (and embarrassing Christmas party behavior) aside, alcohol consumption is also a major risk factor for some cancers, including head, neck, esophageal, liver, breast and colorectal cancer. However, in a spot of good news, a recent study from the University of Colorado suggests that the chemical resveratrol found in grape skins and in red wine can help block the cancer-causing effects of alcohol.

"Alcohol bombards your genes," says Robert Sclafani, PhD, investigator at the University of Colorado Cancer Center and professor of biochemistry and molecular genetics at the CU School of Medicine. "Your body has ways to repair this damage, but with enough alcohol eventually some damage isn’t fixed."

The body metabolizes alcohol by converting it to acetyl aldehyde, then uses aldehyde dehydrogenase (ALDH) to further convert it to acetic acid, which is excreted. Acetyl aldehyde, a partially processed state of alcohol, is a carcinogen that produces DNA "cross links" that can cause cell death.

If enough alcohol is consumed the body can end up with a backlog of acetyl aldehyde. Increased consumption of alcohol, loss of the ALDH gene that helps the body process alcohol, and loss of the ability to repair DNA cross links all result in increased cancer risk. However, Sclafani says there is something in red wine, that blocks the cancer-causing effect of alcohol and believes resveratrol, a natural chemical found in the skins of grapes and berries as well as in red wine and dark chocolate, is the prime candidate.

The researchers found that resveratrol kills cells with unrepaired DNA damage so they can’t go on to cause cancer. Growing evidence also suggests that resveratrol directly binds to DNA and RNA, activates antioxidant enzymes, prevents inflammation, and kills the cells with the most damage – the cells that have the highest probability of being able to cause cancer.

Before you take this news as carte blanche to quaff red wine by the bucketful, Sclafani warns that the resveratrol in red wine (and other chemopreventive chemicals found in grape seed extract) isn’t a magic bullet that can completely undo the cancer-causing effects of alcohol. However, by killing the most dangerous cells it may decrease the probability that alcohol use will cause cancer.

Interest in using natural compounds to fight cancer and other diseases has been growing in recent years. Resveratrol has also been linked to reduced risk for heart disease, a potential way to fight obesity and slowing down of the aging process.

However other studies, including one from John Hopkins Medicine earlier this year, found that diets rich in resveratrol failed to reduce deaths, heart disease or cancer and suggest health benefits may come from as yet unidentified compounds in foods.

Clinical trials are underway at Colorado University to test the effectiveness of resveratrol in preventing colon and liver cancer. Its ability to prevent and possibly treat head, neck and other types of cancer will also be tested.

The research was published in the November issue of the journal Advances in Experimental Medicine and Biology.